So far you are the only one who has said this, and I have gotten about 30
off-list email
asking us to please keep it on the list "in spite of the crazies". But having
a new list solves both problems.
At 08:16 AM 9/24/2003 -0600, you wrote:
>Marko, thanks for doing this. My inbox was filling up with all of the
>physics discussions that I am only mildly interested in hearing about but
>not on a daily basis. Setting up a separate home was great!
>
>
>
>
>Lynne Nicholson
>
> >From: Mark Millonas
> >Reply-To: Shakuhachi@communication.ucsd.edu
> >To: Shakuhachi@communication.ucsd.edu
> >Subject: advert for new group, and last ever physics related post
> >Date: Tue, 23 Sep 2003 13:45:04 -0700
> >
> >Hi:
> >
> >Some of us have decided to move the physics discussion of bores in
> >relation to the shak elsewhere.
> >If it isn't too annoying I will just relate here my first posting
> >*there* so in case there
> >is anyone on this list that likes the topic and flavor (at least as
> >exemplified by this
> >one posting) they can join us or listen in. I also do this with the
> >hopes that some of the musician
> >and shak makers might help us out on some things if it look like
> >anything they might be interested in.
> >I promise not to post anymore acoustics related (but perhaps
> >culturally charged) stuff here anymore.
> >
> >Anyway, first post at ShakuhachiDesign@yahoogroups.com, last post
> >here.
> >
> >-------------------------------------------------------
> >
> >A possible place to start a discussion might be the following paper:
> >A. H. Benade. On woodwind instrument bores, J. Acoust. Soc. Am.
> >31(2):137-146 (1959).
> >Unfortunately it is BPDF (before pdf) so the only way to get a copy
> >is to go to a university library,
> >or I could scan it if anyone can tell me how to post it here.
> >
> >I think this might be a good place to start both because the results
> >in the paper are particularly simple and because it methodology is a
> >simple
> >example of the one I originally proposed: define the required
> >acoustic features then infer the bores that fit those features.
> >His results are for close-ended woodwinds, but I can go home and see
> >if I can re-do all the proofs for open ended bores. That
> >is, unless someone can point me to a place where this has already
> >been done.
> >
> >There are two acoustic features that Benade uses and will be
> >immediately recognizable to the musician with
> >no mathematical training whatsoever: (1) The first and second
> >resonance of a bore (lower and second register) should have
> >frequencies in the ration of 1:2 (play at exactly one octave apart)
> >and (2) that (1) should hold if you "chop" the bore down to
> >any length (that is, for any fingering where all the holes are
> >closed up to a certain point). So the criteria are that the flute
> >play in tune
> >in the first and second registers for all the basic notes.
> >
> >Criteria (1) requires that the bore have the shape where the
> >cross-sectional area depend exponentially
> >on the length S(x) ~ x^a (a Bessel horn), where a is called the
> >flare constant.
> >If we add (2) this then a = 0 and a = 2 are the *only* shapes that
> >*exactly* satisfy these two requirements.
> >These are cylinders and cones. The shak doesn't fit either of these
> >two categories, but
> >(generally speaking) is a cylinder connected to a reverse cone,
> >connected to something that looks along like a Bessel flair
> >with a>2.
> >
> >It is possible that there are some major compromises going on here
> >in terms of playing, but
> >there are also several ways of relaxing the criteria that could also
> >explain the shape.
> >For example, in the shak we don't need the registers to be in tune
> >for arbitrary lengths
> >of bore, but only for specified lengths corresponding to the notes
> >of the scale: that is for
> >5 lengths of corresponding to the pentatonic scale. Because of this
> >the
> >shape (based just on these most simple criteria) could be morphed.
> >So within this "wiggle room"
> >what kind of shapes would be allowed, and are there any that come
> >close to the traditional shak shape.
> >This is something that could be explored mathematically is anyone is
> >clever enough, but could also
> >be explore via the computer. Furthermore, more experience shak
> >makers my already have a "feel" for this
> >wiggle room, and perhaps they could comment on this, if they are
> >willing.
> >
> >
> >By the way, hopefully nobody remembers but I said something stupid a
> >while back. It *IS* the peaks
> >of the input impedance (not the minima) that correspond to the
> >resonance because that's
> >where the wave bound around and build up rather than pass right
> >through.
> >Sorry about that.
> >
> >Marko
> >
> >
> >_____________________________________________
> >
> >List subscription information is at:
> >http://communication.ucsd.edu/shaku/listsub.html
>
>
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